Is the God of open theism trustworthy?

We're all mind-numbingly familiar with objections to Calvinism, but the flip side is whether the God of open theism is a God who can be taken seriously. Say what you will about Calvinism, but that's a God to be taken seriously (if Calvinism is true). But the God of open theism is more like a comic book superhero. 

This also goes to the question of what makes God worshipful. Opponents of Reformed theism say the God of Calvinism isn't worthy of worship.

But how worshipful is the God of open theism? Is he a God you can trust? 

Christians and their loved ones can suffer terrible things in this life. In Calvinism, God is able but sometimes unwilling to protect Christians from horrible things. At we at least believe that God has a good reason for not protecting us in those situations. So he's still trustworthy.

But in open theism you're exposed to terrible harm because the God of open theism is unable to protect you. Indeed, the God of open theism doesn't know the right thing to do because he doesn't know the future, so he doesn't know the long-term consequences of divine intervention. 

It's hard to see how you can have faith in a God like that. He's not in a position to look out for your best interests even if he wanted to. So he can't be an object of unconditional trust. 

Indeed, not knowing the future means he will be mistaken in many cases. He will entertain false expectations. Indeed, some open theist prooftexts say that. 

So following the open theist God can be unintentionally harmful, since he's making stuff up as he goes along. You can be hurt, but he can't (except emotionally). 

In open theism we are in a very real sense, on our own. That has ethical as well as religious ramifications. While that may sound liberating to the shallow-minded, it's terrifying when you consider how vulnerable human beings are. It's a recipe for ruthless self-interest, because it makes life so insecure. In open theism we're living in a minefield.